Posted by on Mar 30, 2015 in Fullsix London Blog, Tech | No Comments

An accessible website will not only be beneficial for your organisation, it will be beneficial for your users. Making your content accessible to users of all abilities can increase the overall reach of organisations’ content and improve usability.

So what exactly is web accessibility and why is it important to optimise your website for accessibility?

Image of a contrast checker tool notifying the user that the chosen text and background colours do not meet the required contrast ratio for partially sighted users

What is Web Accessibility?

Accessibility is the word used to describe whether a product can be used by people of all abilities and disabilities. When websites are correctly designed, developed and edited, all users have equal access to information and functionality. The DDA (Disability Discrimination Act) states that service providers must not discriminate against people with disabilities. A website is regarded as a service and therefore falls under this law, and as such should be made accessible to everyone.

‘We don’t have any disabled users so we don’t need to consider accessibility…’

Sound familiar? The amount of users with disabilities who may face difficulties due to your website’s accessibility are higher than you think:

  • A report by the Royal National Institute for the Blind for the end of March 2014 found that the number of people registered as blind in the UK was 143,385 with 147,715 people registered as partially sighted. Source: RNIB
  • Colour blindness affects approximately 1 in 12 men (8%) and 1 in 200 women in the world. In the UK, this means that there are approximately 2.7 million colour blind people (about 4.5% of the entire population), most of whom are male. Source: Colour Blind Awareness
  • There are 9.4 million disabled people in England, accounting for 18 per cent of the population. 45 per cent are males and 55 per cent are females. Source: EFDS
  • Dyslexia is thought to be one of the most common learning difficulties. It’s estimated that up to 1 in every 10 people in the UK has a certain degree of dyslexia. Source: NHS
  • It is estimated that in England in 2011, 1,191,000 people had a learning disability. This includes 905,000 adults aged 18+ (530,000 men and 375,000 women). Source: learning disabilities foundation
  • There are more than 10 million people in the UK with some form of hearing loss, or one in six of the population.  From the total 3.7 millionare of working age (16 – 64) and 6.3 million are of retirement age (65+). Source: Action on hearing loss
  • Epilepsy can affect anyone, at any age and from any walk of life. In the UK, 600,000 or one in every 103 people has epilepsy. Source: Epilepsy Action

Based on these statistics, there is a very large chance that your users could fit into one (or several) of these categories. Some of the larger organisations are making accessibility improvements to their websites but some organisations are yet to adopt these practices.

The following issues may affect users with disabilities if accessibility is not considered:

  • Users with partial sight may find text hard to read if the colour contrast ratio is not considered.
  • If images or elements do not have the correct attributes and labels, users who rely on screen readers may lose understanding of your website’s content and be unable to navigate the website with ease.
  • If a user is unable to tab through all elements on a website in both directions, they will be unable to navigate your website.
  • Users who are deaf or have partial hearing will be unable to understand all content if there is not a visual equivalent.

Accessibility means good usability

Accessible websites not only benefit users with disabilities, they also benefit the everyday user. 5.93% of the population are still using IE8 and IE9 legacy browsers instead of smart browsers. Legacy browsers do not have support for new technologies and therefore legacy browser users may not have access to some of your website content and functionality, affecting the overall user experience. The usability and ‘feel’ of a website can also be improved by adhering to the basic principles of accessibility.

The following issues may affect the everyday user if accessibility is not considered:

  • Users with poor/slow connections may choose to view a text only version of your site. If your site contains lots of images of text, the user will lose this information.
  • Users with older web browsers may not be able to use all functionality on your site if you are using the latest technologies and languages which are not supported by older browsers.
  • Some content or functionality may be lost if the user has javascript turned off in browser. To an end user, this may appear as a bug.
  • Usability issues such as informing the user of their location on the website or having meaningful error messages can improve the users experience.

Image of example error messages used on a form

How can we ensure we are accessible?

The W3C (World Wide Web Consortium) have collated a set of accessibility guidelines to consider when building web applications. The Web Content Accessibility Guidelines establishes a set of success criteria for software development that is used to help people with different types of disabilities when viewing content via the web. Web accessibility testing is a subset of usability testing which considers the usability of websites for users with disabilities. The guidelines and success criteria are organised around four principles: Perceivable, Operable, Understandable and Robust (POUR).

Understanding the POUR Principles

The four principles of accessibility (Perceivable, Operable, Understandable and Robust) lay the foundation necessary for anyone to access and use web content. Anyone who wants to use the web must have content that is:


Information and user interface components must be presentable to users in ways they can perceive. Users must be able to perceive the information being presented to them – it can’t be invisible to all of their senses.


  • Provide text alternatives for any non-text content
  • Provide alternatives for time-based media
  • Separate content from style
  • Make it easier for users to see and hear content

User interface components and navigation must be operable. The interface cannot require interaction that a user cannot perform.


  • Make all functionality available from a keyboard
  • Provide users enough time to read and use content
  • Do not design content known to cause seizures
  • Provide ways to help users navigate, find content and determine where they are

Information and the operation of user interface must be understandable. The user must be able to understand the information as well as the operation of the user interface.  Considerations:

  • Simplify text content
  • Web pages operate in predictable ways
  • Help users avoid and correct mistakes

Content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies. As technologies evolve, the content should remain accessible.

Know your A, AA, AAA’s

For each accessibility guideline a level of A – AAA is defined. The ‘A’ level is used as a form of measurement to define the level of accessibility your website is adhering to. In order for your website to comply with the accessibility guidelines, all guidelines for the chosen level must be met.

  • Level A – The lowest level of accessibility, covering the most common issues for users with disabilities.
  • Level AA – The secondary accessibility level that includes both A and AA guidelines.
  • Level AAA – The highest level of accessibility that includes A, AA and AAA guidelines. If these guidelines are met, the website should be accessible for all users with disabilities.

Large organisations tend to strive for level AA accessibility compliance as this caters for the majority of users of all abilities whilst not dramatically increasing the project timescale.

Key disabilities to consider when accessibility testing

When accessibility testing, it’s important to think from the perspective of a person who has the disability. This allows you to test common user stories that would be carried out by the user. Key disabilities to consider when testing a website are:

  • Blind or partial blindness – Blind or partially blind users cannot use a mouse therefore require a keyboard and screen reader to navigate through the page.  All text needs to be of readable size for those with a screen magnifier.
  • Colour blindness – Colour blind users may not be able to see coloured links or colour highlighted text. In addition to this, some foreground colours can blend into the background making the foreground invisible.
  • Epilepsy – Epileptic users cannot view content that flashes excessively as this can cause seizures.
  • Deaf – Deaf users cannot hear media play, therefore require text alternatives for any sound or media that contains speech.

Image of bbc iplayer playing the Apprentice with subtitles switched on

At what stage of the project should we consider accessibility?

It is important to consider accessibility at the beginning of any project during the requirements gathering, user experience and design stages. Exit criteria for accessibility testing should be defined by QA at the start of the project. The benefit of considering accessibility early is that potential accessibility issues can be flagged and resolved before development begins which will cost less time in the long run.


Finally, we should never forget our target audience: the end user.

Samantha Bird